The end of the earth

  As life, we all know our ultimate end: everyone will die. The same is true for celestial bodies. Although their life span is hundreds of millions of years, they will also be ruined.
  When the sun burns the hydrogen in the core, it gradually heats up. The current sun is about 30% brighter than the sun that was born 4.6 billion years ago, and it will become brighter. Therefore, the fate of life on earth is already doomed-they will eventually be reduced to ashes in the intense heat of the sun. The earth will once again become a dead rocky planet.
  However, let’s not look so far. Take a few minutes to think about the last journey of the earth. Obviously, the end of life will not be a simple process of becoming zero. During this period of time, new and strange life forms will emerge. So which creatures will survive longer on this scorched planet? Where will they hide? What does our blue planet look like in the last days? What will be the fate of our humanity? Can we avoid our own demise?
  Initial studies
  in order to put forward the “Gaia hypothesis” world-famous British scientist James Lovelock, first consider the impact on the Earth’s sun gets brighter. In 1982, he and his friend Michael Wittfield pointed out a very important chemical reaction in a paper-carbon dioxide in raindrops reacted with silicates in rocks to produce carbonate solids. This process is called weathering. Weathering consumes carbon dioxide in the atmosphere, and the higher the temperature, the more rain and the faster the weathering speed.
  They believe that as the earth warms, the rate of weathering should accelerate, which will eventually lead to a very low carbon dioxide content in the atmosphere, making photosynthesis impossible for plants. Of course, the reduction of carbon dioxide content in the atmosphere will inhibit the greenhouse effect and prevent the temperature from rising rapidly, but this is only a short-term effect. Over time, this effect will eventually be masked by the sun’s constant brightness.
  No photosynthesis means no plants, which is not good news for animals. Lovelock and Wittfield believe that the complete extinction of life on Earth may take another 100 million years, and 100 million years is just a blink of an eye on the geological time scale. Although the basic idea has not changed, current scientists believe that that day will not come so soon. It may take 600 to 900 million years before the carbon dioxide content in the atmosphere is lower than the content necessary for photosynthesis of plants.
  Earth’s timeline
  Recently, Cornell University astrobiologist Jack O’Malley – James, together with other scientists, we know to take advantage of the sun, earth and biological knowledge, drafted a biosphere on Earth the next 40 billion years Timeline.
  O’Malley James said that this is a bit like life is evolving in reverse. Animals are becoming smaller and simpler. Some species may live better than others. For example, after the earth warms, migratory birds may find cooler and higher areas more easily than other animals due to their flying ability. Creatures in the ocean may live slightly better than those on the ground, because it takes more time for water to heat up than air.
  In order to adapt to extreme environments, organisms may become very different from what we know. For example, animals may evolve shells, like turtle shells, that contain iron minerals to isolate the strong radiation from the sun. Perhaps, a large water bag has evolved on the back of some animals to protect the internal organs, because water can also isolate radiation.
  In the most likely scenario, once all vertebrates on land and in the sea die, the remaining life will be only the invertebrates in the sea and the microorganisms that accompany them. O’Malley James believes that the last animal will be a tubular worm living near the deep-sea hydrothermal vent.
  After 1 billion years, things will get worse and worse. By then, the average global temperature will reach 47°C. The ocean will evaporate rapidly, and the extra water vapor in the atmosphere will trigger an uncontrolled greenhouse effect. Microorganisms will adhere to the decreasing water environment. Microorganisms in tropical regions will be extinct first, and eventually in second-tier regions will also become extinct. For a while, the top of the mountain and the underground ice cave will become a refuge from the heat. The last refuge of life will be located deep underground, where the microbes will barely survive until-according to the most optimistic estimate-after 3 billion years, they will also be completely extinct.
  Sector and the impact of the moon
  , however, the reality is often very complex, have a great impact on the future direction of some of the factors that have Earth. First of all, recent research suggests that our understanding of weathering may be problematic, and this will disrupt O’Malley James’ estimate of time. Although there is a certain link between the increase in temperature and the increase in carbon dioxide consumption, other factors, such as rock type and acidity, may be more important. Therefore, it is very likely that carbon dioxide will not be consumed as quickly as expected, which means that plants will survive longer than expected, delaying the collapse of the biosphere for hundreds of millions of years, or even longer.
  Plate tectonics can also change the fate of the biosphere. This process is driven by geothermal energy, and the energy comes from the radioactive decay of isotopes deep in the earth. But the decayable matter is limited, so the energy released will slowly decrease. The plate movement will eventually come to an abrupt halt, at which point the mountain will stop rising. After millions of years, the land will be flattened by erosion. This may happen 1 billion to 2 billion years from now. If it happens too early, then the earth may become a water world before it completely dries up.
  The moon will also have a great impact on the earth. It is now moving away from us at a rate of 3.78 cm per year. In the future, sometime between 1.5 billion and 4.5 billion years ago, the moon will not be able to stabilize its axis. At this time, the axis of the earth may be wobbly, which will cause the earth’s climate to often change rapidly. If there were still animals or plants at that time, they might not survive for too long, because the climate is changing too fast, and they cannot adapt to the new environment.
  But there is another possibility. The moon may still have some control over the earth’s axis, and eventually the earth’s axis will stabilize at other angles, but not the current tilt angle (23.5 degrees). The greater the inclination of the earth’s axis, the more obvious the seasonal changes, which may make some areas suitable for life to continue to survive.
  The fate of humanity
  so that we humans would happen? The existing fossil record implies that the future of mankind is not optimistic. On average, from birth to death, a mammal can exist for about 1 million years. It is a very rare thing to exist for tens of millions of years. At present, we humans have existed for about 200,000 years, so we still have a long way to go. However, troubles will continue along the way.
  For example, if the average temperature of the earth rises by 8°C, it will greatly change the human civilization as we know it: the sea level will be 60 meters higher than it is now, and most coastal cities will be submerged; Moving to the poles has made tropical areas basically uninhabitable, which means that the population in the northern and southern hemispheres will be more concentrated than they are now…
  If future humans finally find a way to deal with all this, they will be very much in the new environment. Evolution may happen. In the most optimistic case, with the help of genetic technology, bionic technology and other means, humans in the future may make themselves completely different from humans today. In other words, humans in the future will evolve into a new species.
  In the distant future, if humans or new humans can really survive, then they will definitely try to cool the earth, although the options are very limited. One way to effectively reduce the temperature of the earth is to build a planetary umbrella for the earth. But 4 billion years later, any form of parasol can not stop the sun’s heat. However, there are still some more radical options, such as migrating the earth.
  As the sun brightens, the habitable zone of the solar system-the range where water can exist in liquid form-will move to the edge of the solar system, and the earth will no longer be in the habitable zone. Then, we can also try to move the earth away from the sun and return to the habitable zone again. One feasible way is to use the gravitational influence of comets or asteroids flying to the earth. If arranged properly, you can convert the orbital energy of a comet or asteroid into the orbital energy of the earth to increase the earth’s revolution speed and move outward.
  About 7.5 billion years later, the sun will expand into a red giant star. At this time, some moons of Jupiter or Saturn should be in the habitable zone, and humans can also choose to live there.
  But no matter what, the sun will eventually become a white dwarf and gradually cool down and dim. Therefore, even if we are not roasted to death, we may be frozen to death. Unless, we moved to a habitable place outside the solar system.